// Copyright 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "cc/test/skia_common.h"

#include <stddef.h>

#include "cc/playback/display_item_list.h"
#include "third_party/skia/include/core/SkCanvas.h"
#include "third_party/skia/include/core/SkImageGenerator.h"
#include "third_party/skia/include/core/SkPixmap.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/skia_util.h"

namespace cc {

namespace {

    class TestImageGenerator : public SkImageGenerator {
    public:
        explicit TestImageGenerator(const SkImageInfo& info)
            : SkImageGenerator(info)
            , image_backing_memory_(info.getSafeSize(info.minRowBytes()), 0)
            , image_pixmap_(info, image_backing_memory_.data(), info.minRowBytes())
        {
        }

    protected:
        bool onGetPixels(const SkImageInfo& info,
            void* pixels,
            size_t rowBytes,
            SkPMColor ctable[],
            int* ctableCount) override
        {
            return image_pixmap_.readPixels(info, pixels, rowBytes, 0, 0);
        }

    private:
        std::vector<uint8_t> image_backing_memory_;
        SkPixmap image_pixmap_;
    };

} // anonymous namespace

void DrawDisplayList(unsigned char* buffer,
    const gfx::Rect& layer_rect,
    scoped_refptr<const DisplayItemList> list)
{
    SkImageInfo info = SkImageInfo::MakeN32Premul(layer_rect.width(), layer_rect.height());
    SkBitmap bitmap;
    bitmap.installPixels(info, buffer, info.minRowBytes());
    SkCanvas canvas(bitmap);
    canvas.clipRect(gfx::RectToSkRect(layer_rect));
    list->Raster(&canvas, NULL, layer_rect, 1.0f);
}

bool AreDisplayListDrawingResultsSame(const gfx::Rect& layer_rect,
    const DisplayItemList* list_a,
    const DisplayItemList* list_b)
{
    const size_t pixel_size = 4 * layer_rect.size().GetArea();

    std::unique_ptr<unsigned char[]> pixels_a(new unsigned char[pixel_size]);
    std::unique_ptr<unsigned char[]> pixels_b(new unsigned char[pixel_size]);
    memset(pixels_a.get(), 0, pixel_size);
    memset(pixels_b.get(), 0, pixel_size);
    DrawDisplayList(pixels_a.get(), layer_rect, list_a);
    DrawDisplayList(pixels_b.get(), layer_rect, list_b);

    return !memcmp(pixels_a.get(), pixels_b.get(), pixel_size);
}

sk_sp<SkImage> CreateDiscardableImage(const gfx::Size& size)
{
    return SkImage::MakeFromGenerator(new TestImageGenerator(
        SkImageInfo::MakeN32Premul(size.width(), size.height())));
}

} // namespace cc
